GoddessN wrote:What are the best ways to live with a partner who has BPD.
I don't think there is a single answer to that question. It would depend on the individual and just because they fit the BPD category best, doesn't necessarily mean they would respond in the same way as the next person with BPD. All I could suggest would be to learn more about it generally, but also try to discuss (if they are willing) what it is like for the partner.
GoddessN wrote:And if we find our partner has cheated on us, should we immiediately leave or we should stay a little longer because the partner did it because of BPD?
I don't think it's ok to use BPD as an excuse for behaviour that is hurtful or unacceptable to the other person. If the person had no awareness of their problems at all, someone on the outside might be able to say it's related to BPD. But if they cheated, were caught out, then said "it's not my fault, it's my BPD" then I feel like that is just using MI as an excuse for doing something hurtful. Not everyone with BPD cheats. Yes some do, but not all.
My advice to partners would always be that they have to decide what is best for themselves. If cheating is unacceptable to you as a partner in the relationship, then it is unacceptable. If you can forgive it once because you know they have issues with this, then work at that. Others might be ok with more open relationships. I guess my answer would be to work out where your limits are and stick to them. Much easier said than done sometimes though.